Stereochemistry of meso-alpha,epsilon-diaminopimelate decarboxylase reaction: the first evidence for pyridoxal 5'-phosphate dependent decarboxylation with inversion of configuration.
The stereochemistry of the decarboxylation of meso-alpha,epsilon-diaminopimelate catalyzed by meso-alpha,epsilon-diaminopimelate decarboxylase (EC 4.1.1.20) of Bacillus sphaericus was determined by stereochemical analyses of [6-2H]-L-lysine produced by the reaction in D2O. The product [6-2H]-L-lysine was converted to levorotatory methyl 5-phthalimido[5-2H]valerate by the reactions not affecting the absolute configuration of the asymmetric carbon atom. By contrast, methyl 5-phthalimido[5-2H]valerate derived from [2,6-2H2]-L-lysine, which was produced from [2,6-2H2]diaminopimelate by decarboxylation in H2O, was dextrorotatory. The authentic methyl (R)-5-phthalimido[5-2H]valerate prepared from L-glutamate with glutamate decarboxylase was levorotatory. These results indicate that the meso-alpha,epsilon-diaminopimelate decarboxylase reaction proceeds in an inversion mode. The deuterium label in [6-2H]-L-lysine was fully conserved during the conversion into pelletierine through [1-2H]cadaverine by the stereospecific diamine oxidase reaction. Thus, the enzymatic decarboxylation of meso-alpha,epsilon-diaminopimelate occurs with inversion of configuration in contrast to the other amino acid decarboxylase reported so far.
D001407:Bacillus / Q000201:enzymology*; D001426:Bacterial Proteins; D002103:Cadaverine; D002262:Carboxy-Lyases / Q000378:metabolism*; D003903:Deuterium; D007700:Kinetics; D008239:Lysine; D010880:Piperidines; D011732:Pyridoxal Phosphate / Q000494:pharmacology*; D011865:Radioisotope Dilution Technique
D001426:Bacterial Proteins; D010880:Piperidines; C008195:isopelletierine; D011732:Pyridoxal Phosphate; D003903:Deuterium; D002262:Carboxy-Lyases; C079912:LysA protein, Bacteria; C020031:diaminopimelic acid decarboxylase; D008239:Lysine; D002103:Cadaverine